The Research Of High-performance YSZ-based Mixed-potential-type Sensor

Mixed-potential-type gas sensor based on yttrium stabilized zirconia (YSZ) andoxide sensitive electrode which has potentially important application in vehicleinspection and atmospheric environment has high sensitivity, high selectivity, lowdetection limit, good chemical stability and thermal stability. In this paper, three kindsof high performance mixed-potential-type sensor have been developed from threeaspects as follows: the preparation of high performance sensitive electrode materials,the construction of high performance three-phase-boundary and the matching betweensensitive electrode materials with three-phase-boundary.First of all, a series of spinel structure sensitive electrode materials (NiMn2O4,NiCr2O4and NiFe2O4) have been prepared by solvent evaporation method, and H2Ssensor has been manufactured with these sensitive electrodes. Through researchingthe influence of reaction conditions and sintering temperature on the properties ofsensor, NiMn2O4prepared by solvent dropping speed of0.75ml/min and sinteringtemperature of900℃has complete hollow structure, and the sensor with this kindof NiMn2O4shows good sensitivity to500ppb-2ppm H2S under500℃. TheΔ Vvalue to1ppm H2S is-76mv. In addition, the device also shows a good repeatabilityand selectivity.Secondly, high performance three-phase-boundary is constructed by laser directwriting technology, and NO2sensors have been manufactured with this kind of YSZsubstrate. The research focuses on the influence of groove spacing on the performanceof the device. The results show that the NO2sensors with YSZ of130μ m groovespacing has the best performance to5-500ppm NO2under800℃. The Δ V valueto100ppm NO2is about100mV, and recovery time is about8seconds. In addition,the device keeps the good long-term stability. Finally, NO2gas sensor is manufactured with NiO which is made byhydrothermal method and sintering method and YSZ which is proceed by laser. Thekey research focuses on matching between material particle sizes withthree-phase-boundary.Above all, this thesis explores the new strategy, new technology and newsolutions to improve the performance of YSZ based mixed-potential-type sensorthrough the development of special structure sensitive electrode materials, theconstruction of high performance three-phase-boundary and the matching betweensensitive electrode materials with three-phase-boundary. It helps to realize theefficient detection to H2S and NO2.